Field of the Invention
The present invention relates to a method of manufacturing an electronic device and a method of manufacturing a photoelectric conversion device.
Description of the Related Art
In Japanese Patent Application Laid-Open No. 2011-124454, there is described a method of manufacturing a solid-state image pickup device. The solid-state image pickup device includes an image pickup region in which a photodiode and the like are formed, and a peripheral circuit region in which a scanning circuit and the like are formed. There may be a difference in density (area of a wiring pattern formed per unit area) between a wiring pattern formed in the image pickup region and a wiring pattern formed in the peripheral circuit region. In a solid-state image pickup device, the density is often higher in the peripheral circuit region than in the image pickup region. When an insulating layer is formed on such a wiring pattern and a level difference caused at that time is reduced by planarization using chemical mechanical polishing (CMP), the image pickup region has a film thickness distribution therein. A difference in optical path length due to the film thickness distribution may cause color unevenness.
Therefore, in the manufacturing method described in Japanese Patent Application Laid-Open No. 2011-124454, part of the insulating layer in the peripheral circuit region is etched out, and after that, a surface of the insulating layer is planarized by CMP. In Japanese Patent Application Laid-Open No. 2011-124454, there is a description that this can reduce variations in film thickness after the planarization of the surface of the insulating layer between the image pickup region and the peripheral circuit regions, to thereby uniformize optical characteristics.
When the surface of the insulating layer is planarized by CMP as in the manufacturing method described in Japanese Patent Application Laid-Open No. 2011-124454, there are cases in which not only the insulating layer but also an electrode forming the wiring pattern is shaved away. The shaved electrode may cause a poor connection in wire bonding process or of variations in wiring resistance.